Sleep and ADHD

Circadian rhythms vary in attention deficit hyperactivity disorder

(RxWiki News) After a night of fitful sleep concentration isn’t always the easiest. In a recent study researchers looked at the relationship between Attention Deficit/Hyperactivity Disorder (ADHD) and impaired sleep. 

Attention deficit/hyperactivity disorder comes with its own circadian rhythm. A new study explored movements and genes and discovered a difference in the expression of circadian system in those with ADHD when compared to unaffected individuals.

"Talk to your therapist if sleep troubles affect your life."

Circadian rhythms express themselves biologically as “clock genes,” producing endocrine as well as physiological and behavioral outputs on a 24-hour cycle. Using saliva to measure cortisol and an actigraph to measure sleep movements in patients, doctors looked at an ADHD experimental group and an age/sex-matched control group to determine the exact differences.

An actigraph, attached to a patient's wrist, allowed researchers to measure gross motor activity, while mucous swabs determined the levels of cortisol and melatonin in the saliva, as well as the rhythmic expressions of clock genes BMAL1 and PER2. Results showed that the hyperactivity did indeed affect sleep:

  • The actigraph measured movements in ADHD adults during both nighttime and daytime sleep.
  • Adults with ADHD moved frequently throughout their sleep cycle, with shorter periods of uninterrupted sleep.
  • Cortisol, a stress-hormone sent to restore balance, showed significantly phase-delayed rhythms in the test group.
  • The circadian rhythms found in the control group could not be found in the clock genes of ADHD patients.  

Study results illustrated dramatic differences in sleep patterns and quality in those without the disorder compared to those with the disorder. The study's researchers suggest "modulation of circadian rhythms may represent a novel therapeutic avenue in the management of ADHD," although the advice may not be as novel as thought.  

According to a 2005 study available on the U.S. National Library of Medicine, the effects of sleep deprivation on the endocrine system and metabolic functions have been known for years.

The study highlights increased cortisol levels as well as shorter periods of restorative sleep regardless of overall duration, proving the effects of sleep deprivation to be similar to accelerated aging.

Those with ADHD should speak with their doctor especially if having trouble sleeping, in order to receive the necessary treatment. 

Review Date: 
November 23, 2011